Low power timekeeping system

Abstract

A low power timekeeping system utilizes a state machine to first read seconds stored in a RAM and update seconds and then determine if the minutes requires updating. If the minutes do not require updating then the sequencer stops operation until the next update cycle. Similarly, the minutes, hours, days of the week, date of the month, month, and year are updated only as needed in each update cycle thereby lowering the power requirement needed by the timekeeping system.

What is claimed is: 
     
       1. A method for keeping time comprising the steps a) in response to a start command reading seconds data from a memory;   b) determining if said seconds data is 59 seconds;   c) incrementing said seconds data;   d) storing said seconds data;   e) if said seconds data was determined to be 59 seconds in step b), then (i) reading minutes data from said memory;   (ii) determining if said minutes data is 59 minutes;   (iii) incrementing said minutes data;   (iv) storing said minutes data; and   (v) if said minutes data was determined to be 59 minutes in step e) (ii), then reading hours data from said memory, incrementing said hours data, and storing said hours data.     
     
     
       2. The method set forth in claim 1 further including the steps of: a) if the hours data, before being incremented, was 11 o'clock p.m., then i) reading days of the week data from said memory;   (ii) incrementing said days of the week data;   (iii) storing said days of the week data;   (iv) reading date of the month data;   (v) determining is said date of the month is the last day of the month;   (vi) incrementing said date of the month data;   (vii) storing said date of the month data; and   (viii) if said date of the month data was determined to be the last day of the month in step a) (v), then reading months data from said memory, incrementing said months data, and storing said months data.     
     
     
       3. The method set forth in claim 1 further including the steps of: a) reading seconds data and alarm data from said memory   b) determining if said seconds data and said seconds alarm data match;   c) if said seconds data and said seconds alarm data match, then (i) reading minutes data and minutes alarm data from said memory;   (ii) determining if said minutes data and said minutes alarm data match; and   (iii) if said minutes data and said minutes alarm data match in step b) (ii), then reading hours data and hours alarm data from said memory, and determining if said hours data and said hours alarm data match.     
     
     
       4. A method for keeping time in a timekeeping system which includes a sequencer, a memory, and an accumulator connected to each other by a data bus comprising the steps of: a) placing seconds data onto said data bus by said memory;   b) reading said seconds data by said accumulator;   c) incrementing said seconds data in said accumulator;   d) placing said incremented seconds data onto said data bus by said accumulator; and   e) storing said incremented seconds data in said memory and holding said incremented seconds data on said data bus by said memory at least until a next read operation by said memory or a next write operation by said accumulator.